diff --git a/BeWoPlanerChat/bewoplaner-chat-android/build.gradle b/BeWoPlanerChat/bewoplaner-chat-android/build.gradle
index b39a065..f70304d 100644
--- a/BeWoPlanerChat/bewoplaner-chat-android/build.gradle
+++ b/BeWoPlanerChat/bewoplaner-chat-android/build.gradle
@@ -6,7 +6,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.4.1'
+        classpath 'com.android.tools.build:gradle:3.4.2'
         classpath 'io.realm:realm-gradle-plugin:5.3.0'
 
         // NOTE: Do not place your application dependencies here; they belong
diff --git a/ChatController/ChatMainControl.xaml.cs b/ChatController/ChatMainControl.xaml.cs
index b7c34f2..8b14784 100644
--- a/ChatController/ChatMainControl.xaml.cs
+++ b/ChatController/ChatMainControl.xaml.cs
@@ -40,7 +40,22 @@ namespace ChatController
 
         private readonly Dictionary<int, SyncFileInfoStruct> _GroupId2DateTime = new Dictionary<int, SyncFileInfoStruct>();
 
-        public Window ContainingWindow { get; set; }
+        private Window _ContainingWindow;
+
+        public Window ContainingWindow
+        {
+            get => _ContainingWindow;
+
+            set
+            {
+                _ContainingWindow = value;
+                if(value != null)
+                {
+                    _ContainingWindow.Deactivated += ContainingWindowOnDeactivated;
+                    _ContainingWindow.Activated += ContainingWindowOnActivated;
+                }
+            }
+        }
 
         private Chat _Chat;
         private CurrentContact _CurrentContact;
@@ -59,6 +74,8 @@ namespace ChatController
 
         private bool _IsDesktopVersion = true;
 
+        private bool _IsInBackground;
+
         public ChatMainControl()
         {
             InitializeComponent();
@@ -66,6 +83,16 @@ namespace ChatController
             ReloadGruppen.Visibility = Visibility.Collapsed;
         }
 
+        private void ContainingWindowOnDeactivated(object sender, EventArgs e)
+        {
+            _IsInBackground = true;
+        }
+
+        private void ContainingWindowOnActivated(object sender, EventArgs e)
+        {
+            _IsInBackground = false;
+        }
+
         public void InitMitChatdaten(ChatDatenUebergabe cdu)
         {
             _Chat = new Chat(cdu);
@@ -119,6 +146,13 @@ namespace ChatController
                 {
                     DisposeAndRemoveNotification((NotifyIcon)sender, pGroupId);
 
+                    if (_ContainingWindow.WindowState == WindowState.Minimized)
+                    {
+                        _ContainingWindow.WindowState = WindowState.Normal;
+                    }
+
+                    _ContainingWindow.Activate();
+
                     SelectContact(_ContactList.FirstOrDefault(f => f.GroupId.Equals(pGroupId)));
                 };
 
@@ -202,7 +236,12 @@ namespace ChatController
 
             AktChatUserList.Items.Add(currentContact);
             _CurrentContact = currentContact;
-            
+
+            if(Clientlist.Items.Contains(pContact))
+            {
+                Clientlist.SelectedItem = pContact;
+            }
+
             var chatMessages = _Chat.LoadChatMessagesForContact(currentContact);
             
             ChatListBox.ItemsSource = chatMessages;
@@ -667,7 +706,8 @@ namespace ChatController
                                     contact.ReceivedMessage = newContact.ReceivedMessage;
                                     contact.TimeStamp = newContact.TimeStamp;
 
-                                    if (Clientlist.SelectedItem != null && !((Contact)Clientlist.SelectedItem).GroupId.Equals(newContact.GroupId) || Clientlist.SelectedItem == null)
+                                    // TODO: Prüfen, ob die App im Hintergrund oder minimiert ist
+                                    if ((Clientlist.SelectedItem != null && !((Contact)Clientlist.SelectedItem).GroupId.Equals(newContact.GroupId) || Clientlist.SelectedItem == null) || _IsInBackground)
                                     {
                                         ContainingWindow.Icon = Utils.GetImageSourceFromIcon(Resource.oC_favico_NewMessage);
                                         ShowNotification(newContact.Name, "Sie haben eine neue Nachricht", newContact.GroupId);